Method of operating internal-combustion pumps.



UNITED, STATES PaTENT OFFICE,

HENRY M. CHANGE AND THOMAS M. CHANCE, OF PHILADELPHIA, PENNSYLVANIA.

METHOD OF OPERATING INTERNAL-COMBUSTION PUMPS.

No Drawing.

To all whom it may concern:

Be it known that we, HENRY M. CHANon those types in which said body of liquid acts upon a mechanical actuator such as a piston or plunger but is also applicable to those types in which said body of liquid acts directly upon the combustible mixture.

Our invention may be usefully employed in operating the internal combustion pump described in an application for patent for method of pumping liquids, Serial No. 575,669, filed Aug. 5th, 1910, by Thomas M. Chance, and in operating internal combustion pumps of the types described in applications for patents filed by Henry M. Chance and Thomas M. Chance for method of pumping liquids, Serial No. 590,790, filed Nov. 5th, 1911, for method of pumping liquids, Serial No. 616,080, filed March 22nd, 1911, for method of pumping liquids, Serial No. 620,804 filed April 13th, 1911, and for method of operating internal combustion pumps Serial No. 625,365, filed May 5th, 1911, all of which five applications describe methods of pumping liquids in which the momentum of a moving body of liquid may be used to compress a combustible mixture, but we do not therein describe or claim the method herein claimed and do not herein claim any of the methods therein described. 3

In the operation of internal combustion Specification of Letters Patent.

Patented May 14, 1912.

Application filed May 16, 1911. Seria1 No. 627,563.

nition of the compressed combustible mixture. We have, however, discovered that many of the objections to pro-ignition which apply to the operation of some types of internal combustion engines do not apply to the operation of internal combustion pumps of the above described types, and we find that increased thermo-dynamic efficiency can be obtained, and greater certainty of ignition secured, by compressing the combustible mixture to such pressure as will produce a temperature suflicient to ignite it. To effect this, the return or compression stroke of the oscillating body of liquid must be actuated by such pressure and through such stroke as will be sufficient to store in said body of liquid enough energy to carry the compression of the charge of combustible mixture up to that at which said charge will ignite. The temperature and compression necessary to effect ignition will vary with the nature of the combustible mixture, and with the temperature of the power chamber and other bodies with which said body of combustible mixture is in contact.

We effect the ignition of the combustible mixture by making the accumulator pressure, used as a source of energy by which said compression is effected, at least equal to the mean efiective pressure necessary to produce the required temperature, or by adjusting the stroke of the oscillating body of liquid, or by so proportioning the size of the pump piston to that of the power piston as to produce the desired result. When the return-stroke of the body of liquid is eflected by a power impulse from another power chamber, the same result can be obtained by directly imparting to this body of liquid the energy necessary to efiect such compression.

Our method of operation therefore consists in making the energy transmitted to the combustible mixture by the returnstroke of said body of liquid such that the final pressure produced in the combustion chamber will not be less than that necessary to raise the temperature of the combustible mixture to the point at which said mixture will ignite, said temperature depending upon the temperature of the combustion chamber or other bodies with which said combustible mixture is in contact.

In operating internal combustion engines by the system of ignition in which the rise in temperature due to compression is utilized for igniting the combustible mixture, great diflicult-y is experienced in causing the ignition to occur at precisely the right point in the stroke, for if the volume of mixture and the clearance space be so proportioned as to give the required temperature at the right point of the stroke under normal running conditions, the compression temperature will not be high enough to cause ignition when attempting to start the engine with the cylinder cold or when there is a slight leak through the piston rings. Hence, engines so operated must be designed normally to produce a higher temperature than that actually required for ignition, so that with a cold cylinder or slightly leaky rings it will be possible to start the engine. Such excess of temperature is likely to cause premature ignition of the charge, tending to reversal of rotation, throwing great strains upon the crank pin and other moving parts and reducing the effective power of the machine. It is further apparent that such system of ignition cannot be used if a wide control of power range is to be effected by throttling the volume of explosive mixture, for if the mixture be reduced in quantity to less than a certain volume, the stroke of the piston and the clearance being fixed, the compression temperature when a small volume only of explosive mixture is admitted to the cylinder will be less than that necessary for ignition.

In operating pumps in which a body of liquid acts directly upon a combustible mix ture to compress it prior to ignition, the splashing of liquid upon the igniting devices and the immersion of such devices in the liquid are difliculties which are not readily overcome, and to reduce these to a mini mum it becomes necessary to limit the speed of operation to one at which the liquid will not prevent or retard the ignition of the charge. In operating those types of pumps in which a body of liquid is used as a flywheel to transmit energy to compress a combustible mixture, whether such energy be applied to the combustible mixture, directly or by means of a piston, the stroke of which is not mechanically limited, all of the energy stored in said moving body of liquid is available for compression of the charge, and the length of stroke is determined by this energy and by the volume of combustible mixture which is to be compressed,and not as in an ordinary flywheel engine by the throw of the crank. If to pumps of these types we apply the described method of self-ignition by compression, we find the conditions diifer from those obtaining to the ordinary fly-wheel internal combustion engine, for under proper conditions of operation the liquid fly-wheel nearly comes to rest when ignition occurs, and the small residual energy it still rea body of liquid is used as a fly-wheel either directly or by means of a piston to compress a combustible mixture the volume and temperature to which the combustible mixture is compressed at the end of the stroke can be controlled by varying the energy applied to, transmitted by and stored by said body of liquid during said stroke. e utilize such control by so proportioning the body of liquid and the energy applied to it as to effect the desired conditions whereby ignition is produced at the desired point at or near the end of the compression stroke, varying these as may be required so that the proper conditions may be preserved irrespective of the volume of the combustible mixture which is compressed and ignited. Such control is not possible in the operation of internal combustion engines as commonly constructed and operated, and in the absence of such control 7 1. The hereinbefore described method of operating internal combustion pumps in which a moving body of liquid acts upon an actuator to effect compression of the combustible mixture prior to the ignition thereof, which consists in transmitting energy to said body of liquid to effect the return-stroke of said body of liquid; in causing said body of liquid to attain relatively high velocity; in so proportioning the dimensions and velocity of said body of liquid that the energy represented by the mo mentum of said body of liquid and the energy directly transmitted by said body of liquid will be suflicient to compress said combustible mixture to a pressure such that the rise in temperature produced by said compression will be sufiicient to cause said combustible mixture to ignite; in so compressing said combustible mixture and in causing the ignition of said combustible mixture by the rise in temperature produced by the compression thereof.

2. The hereinbefore described method of operating internal combustion pumps in which a moving body of liquid acts directly upon a combustible mixture to effect the compression of said mixture prior to the ignition thereof, Which consists in transmitting energy to said body of liquid to effect the return-stroke of said body of liquid; in causing said body of liquid to attain relatively high velocity; in so proportioning the dimensions and velocity of said body of liquid that the energy represented by the momentum of said body of liquid and the energy directly transmitted by said body of liquid Will be suflicient to compress said combustible mixture to a pressure such that the rise in temperature produced by said compression Will be sufiicient to cause said combustible mixture to ignite; in so com- 15 In testimony whereof We have hereunto 20 signed our names at Philadelphia, Pennsyl- Vania, this fifteenth day of May 1911.

HENRY M. CHANCE. THOMAS M. CHANCE.

Witnesses v E. R. BARNARD, E. M. LEAGH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

